Harvesting solar energy is a great way to generate sustainable power, but unfortunately solar cells are far from being as efficient as they might be. Currently, commercially available solar cells can convert about 25 percent of sunlight into electricity, and scientists have been trying to create better solar cells for years. One milestone they have been unsuccessfully trying to reach is 50 percent conversion efficiency of solar cells. However, the start-up company Semprius might be on the right track with the stacking technique of solar cells they recently developed.

The idea to stack solar cells in order to make them more efficient is not entirely new, but Semprius has managed to make a huge leap forward with it. They have successfully demonstrated that three semiconductor materials can be stacked on top of a fourth solar cell. Such a stacked device is capable of reaching efficiencies of up to 44.1 percent. Furthermore, this stacking technique allows for the reuse of costly crystalline wafers that multijunction solar cells are grown on, which significantly reduces production costs.

The three key innovations of the technique developed by Semprius are a cheap, fast way to stack cells, a proprietary way to electrically connect cells, and a new kind of glue holding the cells together. The design of Semprius’ stacked solar cells utilizes tiny individual solar cells, each of which measures only a millimeter across. This also helps to bring down the costs while improving efficiency.

The company is certain that in three to five years, they will be able to construct solar cells that will consist of two stacked multi-junction devices, which would yield a total of five or six semiconductors. Such a device could actually surpass the magic 50 percent solar cell efficiency point.

Also, such cells would have a manufacturing capacity of 80 to 100 megawatts a year, and solar cells that can achieve 50 percent efficiency could potentially reach costs of five cents per kilowatt-hour. This is less than the current price of natural gas, which costs 6.4 cents per kilowatt-hour.

Maison Reciprocity, or Reciprocity House, is one of the entrants in this year’s Solar Decathlon Europe competition. In a nutshell, it is an energy-efficient, highly sustainable modular home, which aims to set the standard of low cost, and low impact building in the future. It is a joint effort between Appalachian State University and the French Université d’Angers, and one of only two entries into the competition by US teams this year.

Maison Reciprocity will be constructed using Binderholz Cross-laminated Timber, which is an engineered wood that is a great insulator, and can also carry heavy loads. The doors and windows of the house will be fitted with Eastman Chemical Company Heat Mirror insulating glass (IG), which has lightweight films suspended inside the airspace of the IG unit that work to create multiple super-insulating cavities, without adding extra weight. These cavities help prevent heat loss or heat gain. The center-of-glass thermal performance of these windows is up to R20 (.05 U-value), making them nearly as insulating as walls. The windows also block 99.5% of UV-rays.

The roof of Maison Reciprocity will be insulated using Atlas Roofing Corporation’s tapered and flat ACFoam-II roof insulation, which they chose because it can be used in most roof systems without the need for a thermal barrier, and because it resists heat transfer. For the rest of the insulation needs they chose Atlas Rboard (coated glass-mat faced board), and four types of Roxul insulation, which are made from natural and recycled materials and prevent moisture. Maison Reciprocity’s wall insulation system will be eight inches thick and made of polyisocayanurate (polyiso) and mineral wool.

The house will also have a green roof, which will be located beneath the rooftop-mounted photovoltaic array. In this way the vegetation will have an evaporative cooling effect on the panels, increasing their efficiency by keeping them at a stable temperature.

The house will be energy independent and will feature the Integrated Systems CHORD, which integrates the plumbing, heating, ventilation, and air-conditioning components in a single space. This efficient layout makes it easier to control and optimize all the different systems of the home.

The Solar Decathlon Europe competition will be held in Versailles, France from June to July 2014, and Maison Reciprocity is definitely a project worth rooting for.

Dr. Jon Major, a researcher at Liverpool University has recently made the discovery that the chemical used to make tofu, and bath salts, could also be used to replace one of the most toxic substances, namely cadmium chloride, that are used to manufacture solar cells. Using salts to replace cadmium chloride in solar cell production would also make them much cheaper. His study was published in the journal Nature.

Cadmium chloride is a soluble compound that is expensive to produce and very toxic, which means special care must be made during the production of solar panels, as well as during their disposal after they are no longer useful. Dr. Major has now discovered that this compound could be replaced by magnesium chloride. The latter can be extracted from seawater and is already in use for making tofu, bath salts and de-icing roads.

Magnesium chloride is also safe to produce, and costs only $0.001 per gram as compared to $0.3, which is the cost of producing cadmium chloride. According to Dr. Major, the only way for renewable energy to compete with fossil fuels is by lowering the cost of harvesting it. This was also the key aim of his research.

Right now, the least expensive solar cells are based on a thin film of insoluble cadmium telluride. Without the addition of cadmium chloride, these cells convert only 2 percent of sunlight into energy. But by adding cadmium chloride to them, their efficiency is raised to over 15 percent.

The same result can be achieved if cadmium chloride is replaced by magnesium chloride. Also, the solar cells created using magnesium chloride were made by simply applying it with a spray gun, while applying cadmium chloride has to be done in a fume cupboard in the lab.

While solar sunlight is considered a great source of renewable energy, the solar cells used to collect it are still far from sustainable. Breakthroughs are being made all the time in producing a greener solar cell, and hopefully the day when new, more eco-friendly solar cells become available.

The photovoltaic technology is frequently used to obtain energy these days. Since it was discovered in the 19th century that it is possible to get energy from sunlight, the ways of harnessing solar energy went through many different stages. The first prototype of solar cells was, for example, used to provide the satellite Vanguard I with energy in 1958 and the technology has been used in this area ever since.

The oil crisis demonstrated our dependence on fossil fuels and led to the much needed rethinking of where the energy comes from with a view towards finding dependable sources of renewable energy. Coupled with the nuclear power plant catastrophes and a stronger environmental consciousness also stimulated this wish to use nonpolluting and sustainable sources of energy. Therefore many enterprises and households opted for solar energy, since solar panels can be easily installed on rooftops, where they can harness energy from the sun, which is a limitless source of renewable power. Due to the greater interest and demand it is also important to consider the Solar IRR, solar economic return projects, among others.

Lately, this technology has developed much further than the known uses of solar panels on rooftops and on the ground. One such example is the building of integrated photovoltaics. During World Cup 2014, the company Martifer presented their completed project of a 1.4 MW installation of solar panels on the rooftop of the Mineirão stadium in Belo Horizonte, Brazil. The match on June 14 was the first one ever played in a stadium that obtains its energy from solar panels.

Mineirão stadium was fitted with 6,000 solar panels, and it is the first ever World Cup stadium to be powered entirely by solar energy. This solar power array is capable of producing 1,600 megawatts-hours of electricity per year, which is enough to power 1,200 households. About 10 percent of this electricity will be used in powering the Mineirão stadium, and the rest will pass back into the grid and be used by consumers.

The company Martifer is also currently working on an off-grid system, which is intended for people living in remote areas where it is not possible to connect to the public power grid. In this way, rural areas can be provided with energy. Africa, with its high radiation of the sun has a big advantage over other countries in this respect, and could become the home for such large solar power arrays.

Information about Martifer Solar:

Martifer Solar is a leading global player in Development, EPC and O&M Services in the photovoltaic market.

Their recognized capabilities across the entire value chain enable us to manage all phases of the solar development cycle, from market and site identification to the grid connection and subsequent plant operation.

MARTIFER SOLAR is a Portuguese-based company with presence in more than 20 countries over 4 continents and has implemented 560 MW of solar energy all over the world.

]]>http://www.jetsongreen.com/2014/07/innovative-ways-of-using-solar-panels.html/feed1Solar Powered Tiny Travelling Homehttp://www.jetsongreen.com/2014/06/solar-powered-tiny-travelling-home.html
http://www.jetsongreen.com/2014/06/solar-powered-tiny-travelling-home.html#commentsThu, 19 Jun 2014 22:17:34 +0000http://www.jetsongreen.com/?p=29642Dog trainer Julie Olson found herself in need of a mobile home, so she decided to build a tiny house on wheels. Olson has no architecture training herself, so she made the plans that detailed everything that she wanted her home to have, and sent them to Jason Dietz of Molecule Tiny Homes. It took him about two months to build Olson a home that was in keeping with her specifications. These included 2 loft areas, one of which was to be used as a bedroom, and the other for storage. Olson also wanted a fold out porch, storage stairs, a bathroom and a closet.

The resulting mobile tiny home measures 136-square-feet and is able to provide complete off-the-grid living. It is powered by a rooftop-mounted photovoltaic solar panel, solar batteries, a propane gas tank and a tankless on demand water heater. The home can also easily be hooked up to existing power and water lines. The bathroom is fitted with a composting toilet, as well as a tub, tiny sink and an escape hatch which offers great nature views. The water coming from the tiny home is grey water, which can be used to water a garden, or disposed of by hooking up the home to a city sewer.

The interior is paneled with birch wood paneling, which is quite rigid, and able to withstand the constant movement associated with road travel. The paneling is finished with mineral oils, which works just as well as more toxic wood stain alternatives. The entire kitchen was custom built from wood, since using tiles or any other type of stone in a mobile home is not a good idea due to the fact that it might crack or break on the road. A lot of the fixtures, such as the bathroom and kitchen sinks, were actually purchased from an RV supplier store, since the size is right for a tiny home as well.

The home also has a regular staircase, which makes it easy to get to the loft bedroom. To maximize the available space, a series of storage spaces was built into the side of the staircase. The sleeping loft is 8 by 6 feet, which is big enough for a queen size bed. The tiny house also has vaulted ceilings to appear more spacious. The home has a lot of large windows, to let in as much light as possible, and dispel the feeling of claustrophobia from living in such a tiny home. The ventilation is aided by a ceiling fan that works well to move the air around the house, aided by the wind tunnel created when the windows on both sides of the tiny home are opened.

The tiny house cost $45,000 to build, though Dietz is certain, that this number could be halved if the owner built the home themselves. Part of the reason small homes on wheels cost more per square foot than regular tiny homes, is because road travel requires them to have additional structural support in place. The process of building this tiny home has also inspired Olson to learn how to become a tiny house builder herself. Her plan is to build a bigger house for herself in the next five to seven years.

]]>http://www.jetsongreen.com/2014/06/solar-powered-tiny-travelling-home.html/feed6Small House That is Huge on Sustainabilityhttp://www.jetsongreen.com/2014/06/small-house-that-is-huge-on-sustainability.html
http://www.jetsongreen.com/2014/06/small-house-that-is-huge-on-sustainability.html#commentsSun, 15 Jun 2014 05:14:06 +0000http://www.jetsongreen.com/?p=30250

One of the winners of this year’s American Institute of Architecture’s Small Project Practitioners Knowledge Community 8th annual Small Project Awards is Small House in an Olive Grove designed by Cooper Joseph Studio. The home is located in the Dry Creek Valley near Sonoma, California and functions almost completely off-the-grid.

The house is a 3-storey, 850 square feet home that is located at the top of an olive orchard, hence the name, and is north-facing to minimize heat gain and offer good natural cooling. The house is anchored to the steep hillside with a number of retaining walls and cascading exterior decks, each of which is connected to an interior space. The bedroom is located on the top floor; the mezzanine level holds the kitchen and dining area, while the living area is in the lower level of the house.

The power needed to run the household is provided via a 930 square-foot solar panel field, which was placed on a nearby hillside. This solar panel system is capable of producing 21,578 kWh of electricity per year. The solar field is also elevated 10 feet off the ground and acts as a sun shelter for the agricultural shed beneath it. The Xeriscape plantings around the house are able to conserve water, especially during drought months, and they will require no irrigation once they have stabilized. The storm runoff from the hills is redirected and filtered using a series of culverts, underground piping and grading shifts, which provides a steady source of water.

Most of the façade of the home was left in the original concrete look, though some redwood siding and shading was also added to minimize solar heat gain and provide shade. Large windows were installed throughout the home to maximize natural daylighting,

The house was commissioned by two scientists who were interested in growing olives to produce olive oil, keeping bees for honey, and gardening. They wanted a home that would let them live off the land as much as possible, which is exactly what this house provides.

]]>http://www.jetsongreen.com/2014/06/small-house-that-is-huge-on-sustainability.html/feed4Solar Roadways Could Become the New Smart Gridhttp://www.jetsongreen.com/2014/05/solar-roadways-could-become-the-new-smart-grid.html
http://www.jetsongreen.com/2014/05/solar-roadways-could-become-the-new-smart-grid.html#commentsFri, 23 May 2014 23:47:27 +0000http://www.jetsongreen.com/?p=30057

Two years after being proposed US electrical engineer, Scott Brusaw’s system of solar powered roads is in the second prototype stage, which could lead to wide spread use. Scott’s idea is to cover highways and other roadways with photo-voltaic panels that would collect energy and feed it into a decentralized power grid. If successful, these panels could generate enough energy to power the entire country. Scott is currently raising funds via an IndieGoGo campaign to begin production.

Solar Roadways, as the project is called, is a modular paving system of solar panels, which can withstand loads of over 250,000 pounds. The full size hexagon modular units would be fitted with 36-watt solar panels and have 69-percent surface coverage by solar cells. The Solar Road Panels can be installed on roads, parking lots, sidewalks, bike paths, driveways, playgrounds and more. Homes and businesses can then be connected to this energy grid via driveways and parking lots, and have all their energy needs met. According to Scott’s calculations, nationwide adoption of his Solar Road Panels would produce over 3 times more energy than is used in the US. These calculations are based on the first prototype of the system, which they built on a stretch of road in Idaho.

Apart from energy collection, the roads would also have a number of additional benefits, such as heating to melt the ice and snow, LED lighting to show the road signs and lines, and more. Electric cars could also be charged in the solar panel covered parking lots. The proposed system is modular, meaning that, among other things, in case of damage to one of the panels, only that panel can be replaced.

To get rid of overhead cables the Solar Roadways will also be fitted with so-called Cable Corridors, where fiber optic cables could be installed, which would bring high speed internet to everyone. The project will also tackle the problem of stormwater, which is responsible for more than 50% of the pollution in U.S. waterways. A special section of the Cable Corridors in the roads will be fitted for storing, treating, and transporting stormwater. In addition to that, they also plan to use recycled and repurposed materials as much as possible. For the prototype parking lot they used recycled glass as ten percent of the aggregate in the base layer.

The power grid in the US is in need of modernization and covering the roads with solar panels seems like a great idea. If you want to learn more about the project, visit the IndieGoGo page or the Solar Roadways website.

Blackfriar’s Bridge, which is the largest solar bridge in the world and part of London’s Blackfriar’s railway station, is finally finished. Work on the structure started in 2009 as part of the worldwide energy conservation efforts. The bridge crosses the river Thames and the solar panels that now cover it were installed by the firm Solarcentury.

Blackfriar’s Bridge was fitted with 4,400 photovoltaic panels, more specifically Panasonic 250 Wp panels, which cover the total area of the bridge namely 19,685 square feet. The maximum output of the panels should reach 1.1 MWp (megawatt peak) and is expected to generate 900,000 kWh of electricity per year. This is expected to offset over 50% of the energy needed to power the railway station. The solar panels are fixed and south-facing. The setup will also offset CO2 emissions by an estimated 563 tons annually.

Turning Blackfriar’s Bridge into a solar bridge was also part of a larger refurbishment of the railway station, which was enlarged with several new platforms. To offset the power required for this expansion, the designers decided on the solar bridge to help with the energy needs. Installing the PV array was very difficult, however, since the builders had to installed them on an old, Victorian era bridge, with the railway operating as usual and the river Thames below them. They were faced with many unexpected setbacks, such as corrosion on the arches and being forced to strengthen the existing bridge before they could install the solar panels.

In addition to the overwhelming energy producing benefits of using solar panels, they also have design and architectural benefits. Since the solar arrays are generally unobtrusive, they blend well with the existing architecture. Another great advantage of solar panels, according to the company that completed the work on Blackfriar’s Bridge, is the fact that they can be fitted into even the most complex engineering projects, while they can also be installed over a construction site or a functioning railroad.

During the renovations, the railway station was also fitted with other energy saving measures such as a rain harvesting system and sun pipes that will provide natural lighting throughout the building.

Ray Armstrong’s mountain home in Colorado Springs is a sprawling 5,500 square foot structure, with the living space extending outdoors where the owner’s fish ponds and water gardens are located. Armstrong is an award-winning koi fish enthusiast, and his home uses even more energy since the ponds and tanks, where his fish are, require precise temperature and water regulation. Since such a large home also consumes vast amounts of energy, Armstrong enlisted the help of David Bednarski, owner of Bestway Mechanical in Colorado Springs, to help him install the necessary solar and other technologies to reduce this footprint.

The home is comprised of a lower level and a ground floor. Bednarski commenced his work by first removing the existing forced-air heating system and replacing it with a radiant heating system. The house has a mechanical system that is completely integrated, which means that it heats as well as controls the temperature in all of the 12 indoor zones of the home, as well as the 7 outdoor zones comprised of the ponds, gardens, hot tub and koi fish tanks.

The first stage heating of all the 19 zones and the needed domestic hot water is provided by 10 Apricus AP-30 evacuated tube solar thermal collectors. Seven of these are roof-mounted, while three are wall-mounted. The system also includes a 659-gallon solar storage tank.

For second-stage heating, Bednarski installed a HTP Versa Hydro, which is a 199,000 Btuh high-efficiency boiler that includes a 119-gallon solar heat exchanging storage tank. Once the Versa Hydro senses that solar energy is running low, it slowly starts burning gas to supply the needed energy. According to Bednarski the Versa has, so far, only fired up on low-fire for a few hours during very cold days or overnight. Emergency, third stage heating is provided via a Munchkin MC99, high-efficiency wall-hung boiler, though this one has not yet been needed.

All told, the solar PV array is able to handle 75% of the energy load of the home and the garden. Since the home’s driveway goes uphill, Bednarski installed an 11.5kW SunPower, dual-axis solar PV electric system with onsite and remote Web monitoring capabilities. The dual-axis solar trackers swivel and rotate up and down and from east to west. According to Bednarski, this setup provides 35% to 40% more energy as would be provided by stationary solar panels.

Still in the works is finding a way to decrease the remaining 25% of the energy load of the home. The team is considering installing LED lighting, upgrading the pumps, power factor adjustments, and so on. As for the mechanical system, it now has temporary Caleffi and Taco controls in place, while they plan to install a more permanent Rehau Smart Controls system soon.

A group of researchers at the North Carolina State University (NCSU) have recently successfully developed solar cells that are able to heal themselves. More specifically, the scientists have successfully been able to solve the problem of dye-sensitized solar cells (DSSC), namely that the dyes used to create energy in these cells would eventually be destroyed by UV radiation.

DSSC cells contain a water-based gel core, electrodes, and inexpensive, light-sensitive, organic dye molecules that capture light and generate electric current. The original cells were created by mimicking the photosynthesis process that occurs in the leaves of plants. In trying to solve the problem of the dyes eventually becoming ineffective due to exposure to UV rays, the NCSU scientists again looked to plants for inspiration. The solar cells they developed contain a network of vascular channels that are very similar to the veins in a leaf, which are used to maintain water and nutrient levels throughout the leaf. The researches found that the needed dyes could be effectively delivered and replenished via this network. The dye that had been rendered ineffective by UV radiation can also be removed through this network.

DSSCs are potentially able to generate electricity even at low levels of light, such as in a shady areas or on overcast days. During testing they have also been able to reach efficiencies that are almost equal to the conventional silicon-based solar cells. Through the work of NCSU researchers one of their major drawbacks, namely losing effectiveness over time, has now apparently been solved.

The other major drawback of DSSC design is that they utilize a liquid electrolyte, which has detrimental temperature stability problems. The electrolyte freezes at low temperatures, which ceases energy production and can physically damage the cells. On the other hand, in times of higher temperatures, the electrolyte liquid expands, meaning that the solar panels cannot be sealed properly.

Mainstream use of DSSC cells in the solar power market may not yet be on the horizon, but these cells are currently already being produced on a large scale for powering gadgets and other mobile devices. A number of companies are also considering developing these cells for building applications, such as embedding them in window glass in an effort to prevent heat loss. With the work of NCSU researchers, these cells are now able to maintain their capacity and efficiency over long periods of time, which certainly brings this promising sustainable technology one step closer to a wider application.